Two ships from other companies also have been hit with norovirus in recent weeks in well publicized incidents, leading to the impression that norovirus is a "cruise ship'' disease. It's not, according to the Centers for Disease Control, which says that 1 in every 15 Americans will contract norovirus this year.

My own too-close encounter with the gastrointestinal virus is a case in point. It arrived courtesy of a conference in a hotel in a major U.S. city.

The virus does spread quickly in tight quarters, which is why most cruise lines will require passengers to stay in their cabins until 24 hours after symptoms end. While that probably isn't your idea of a great vacation, it's the responsible thing to do. Typically other members of your party that aren't sick aren't required to stay in the cabin.

So what happens if the bug hits when you're headed to sea?

On Princess' shortened Feb. 4 sailing, passengers received refunds, help with rebooking air arrangements and hotel if necessary, and a 25 percent future cruise credit.

Policies vary from line to line, and sometimes from sailing to sailing, depending on the severity of the outbreak. Often, lines will provide free onboard medical care for passengers struck with the virus, and a Royal Caribbean spokesman said its line will credit passengers for the time they are confined to their cabin (usually a day.)

If you’re feeling sick just before you leave, Carnival Cruises, Royal Caribbean and other lines encourage you to let the pier agent know; they may reschedule your sailing at no charge. That’s not easy though for someone who lives far from the port or embarkation, and policies vary about how arrangements work if you’re feeling sick a day or two before you’re due to leave.

One way to hedge against such complications is travel insurance. After years of fielding letters from travelers whose plans were derailed by illness and accidents, I highly recommend buying travel insurance any time you’ve got more money paid for a trip than you want to give up. Sites such as Squaremouth.com, InsureMyTrip.com and Quotewright.com sells package policies that will reimburse you and your companions if you have to cancel or alter a trip due to illness. To cover pre-existing conditions, most policies must be purchased within 7 days of your initial trip payment.

As for avoiding norovirus, there’s really only one thing you can do: Wash your hands with hot water and soap at every opportunity. Hand sanitizers also help. Antibiotics don’t.